More sophisticated than your diet.

The Castelli Rosso Corsa 9 is just like the Rosso Corsa 13 and 6, but with a medium-height 9cm cuff. Identical to the other versions, they are woven with Meryl Skinlife antibacterial fibers. The sock is thus wicking, will feel dry pretty much in just about every circumstance save a rainstorm. The top of the foot is a diaphanous web, ultra-thin and extremely breathable. In the middle of the foot, the arch area, there is a high-density band woven in. You won't notice any difference in thickness, but you will feel like the sock is becoming one with your foot rather than sliding around between your foot and your shoe. The toe has a flat seam for comfort and the cuff at the top is folded over to keep the sock from slipping.

The Castelli Rosso Corsa 9 Sock comes in three colors: Black, Red, and White. The toes, heels, mid-foot band, and cuff logos are in contrasting colors. Sizes are S/M, L/XL, and 2XL.

Comment on Jeffrey A.'s review:

Just Socks

Fit: Runs large

Well, they are just socks, but they fit tight, and have enough texture to avoid your shoes slipping around. I like these so much that I wear them with my jeans and white tennis shoes. They just feel right.

They run large. I wear size 9.5 (43) shoes and I went with the small socks. The heel cap is in just the right place. I think that medium would have been too large. I am amazed that ANYTHING Castelli fits large - but there you go. Anyway - buy a few pairs, they are one of the most inexpensive Castelli kit pieces.

Comment on Greg Balzer's review:

Great socks

Fit: True to size

Size Bought: XL

I really like these socks. True to size (size 10/44 shoe) and don't notice I'm wearing them. I bought additional pairs after wearing them twice. Can't comment on longevity of item as I've only been wearing them this season

Comment on Nelson G.'s review:

Fits Awesome: Not ideal hot summer sock.

Fit: True to size

I selected these socks for the summer months and they are not as cool as a summer sock should be. The foot is as advertised and fits great and is cool. However, the cuff fabric is double-thick all the way down to the shoe which makes it tighter and hotter than a summer sock should be. Great sock just too much cuff material if you ride in 80-90 heat.

Comment on Gregorio's review:

Like you're wearing nothing at all

Familiarity: I've put it through the wringer

Fit: True to size

Size Bought: Large/XLarge

Cool, light weight, and durable. I've really enjoyed these socks. I've used them for about 2500 miles of use now and have had no issues. They wash well, no holes, and keep your feet cool even in 90+ degree heat. No complaints. I'm a men's 10.5 and got the L/XL

Comment on Eric Watford's comment:

Nice mid length sock

Familiarity: I've used it several times

Fit: True to size

Size Bought: L/XL

I like a mid to high sock for late season riding. I'm glad I checked the other reviews in terms of sizing. I wear a 10.5 US or 44 Euro shoe, I purchased a L/XL in these. I have a short pair of Castelli socks that are XL/XXL that fit similar. Well made, I'd love to see a bit more padding however. Made like a summer sock but in a medium height version.

Comment on Alessandro D.'s review:

Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.

Great Socks. Runs Large

Familiarity: I've used it once or twice and have initial impressions

Very comfortable, thin sock. I wear a size US 12/12.5 and went with the L/XL instead of the XXL the chart said I should wear. Glad I did because even the L/XL is ALMOST too big. I normally pull my socks really tight but can't with these or the heel will go too far.

Comment on Eddie Q's review:

Wicks Well

Familiarity: I've put it through the wringer

These socks rock! They wick well and keep my feet dry and comfortable on long rides. They do exactly what they were designed to do. I like the 9 height. Do your feet a favor get a couple pairs of these.

Comment on Gianni Versace's review:

Awesome sock!

Familiarity: I've used it several times

Fit: True to size

These are perfect height. Not to long, not to short. These will transport moisture away from your skin, thus geeping you cooler in the Summer, and warmer during the shoulder seasons. Dry skin will not blister like wet clammy skin does.

Comment on Gianni Versace's review:

favorite summer socks

Yes these have to be my favorite summer socks. Have 5 pair of these and the fit is superb, lightweight + thin, fit into my road shoes perfectly, no uncomfortable folds, bunching or pulling. Super comfort on long hot summer rides 4-5-6 hrs, no problem. (the fit for me on this product is XXL to fit US size12)

Comment on dewolf's review:

Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.

fantastic socks

These socks are great in every aspect. They fit excellent, keep the feet cool, wick away the sweat and are made excellent from a quality standpoint. The socks are a nice height and look fantastic. I went back and bought several more pairs after receiving my initial order, double thumbs up. I bought the l/xl and wear a size 10 street shoe.

Comment on T Elliott's review:

Castelli Rosso Corsa 9 Cycling Sock

This sock is great if you like an ultra thin sock that holds up very well. Compared to a Defeet sock, I'd say this one is definately thinner but is holding up just as well. I worn my one pair of these for a few rides and I'm close to saying they are my favorite pair of summer socks. Definitely worth the extra bucks (as is pretty much everything made by Castelli).

Comment on Mark Parrett's review:

Okay, I just got a couple pair of L/XLs...

Okay, I just got a couple pair of L/XLs (verified as printed on the sock). I wear a 9.5 US shoe. The size chart says L/XL should fit a 7.5-9.0, but these are about an inch too long for my foot. I've never had anything from Castelli run large. I'm planning on sending them back in for the S/M, but I'm worried they will be too small...size chart says 3.5-7.0! Any thoughts?

Comment on JT's answer:

yes. I'm a US 9.5/10, I bought the L/XL and the heel cup marking (where sock is different color at heel) ends up covering my Achilles tendon when pulled up tight enough to prevent bunching around my toes. I bought the Medium and had a perfect fit. Castelli is bizarre fit wise. Socks are typically much larger and shorts/jerseys much smaller. I'm a huge Castelli fan, just takes trial and error trying to get the best fit. Don't get me started on the way Castelli full zip jerseys vs. 1/2 zip jerseys fit....